Process of dyeing wool black.



invrrnn STATES PATENT OFFICE.

Specification of Letters Patent.

Patented Sept. 4, 1906.

Application filed October 18, 1904. Serial No. 228,988.

To Z7 207210172, it may concern.-

Be .it known that I, FRANZ KoNITzEn, manufacturer, a subject of the Kingof Saxony, and residing at No. 1 Lutherplatz, in Zittau, in the Kingdomof Saxony, German Empire, have invented anew and improved method ofdyeing animal fibers and mixtures of animal and vegetable fibers, asWell as the goods manufactured thereof, by means of oxidationblack, ofwhich the following is a specification.

In dyeing oxidation-black on fabrics made from animal fibers or frommixtures of ani mal and vegetable fibers various difficulties presentthemselves, which are based on the different characters of the twoclasses of fibers. The methods hitherto known attempt to counteract thereducing properties of the animal fibers, and especially the capacity ofthe wool for the absorption of acids, either before the actualoxidation-black process by treatment with acids or oxidizing media, orwith both combined, or by first treating the material with acid, thendyeing by the oxidation proc ess the cotton alone, (an excess of acidand oxidizing medium being used for this purpose,) and then steaming thewool, or by using instead of hydrochlorid of anilin the ferrocyanid ofthe same and developing the black color by steaming.

Careful experiments on dyeing black by the anilin oxidation process haveshown that the difference between the chemical character of animalfibers and that of vegetable fibers is no longer apparent in dyeingblack by the oxidation anilin process, and that consequently animal andvegetable fibers may be padded with the same anilin-black mordant andafterward dyed uniformly black by drying and oxidizing (greening, aging)and subsequent chroming or steaming, it being immaterial whether the twokinds of fibers are dyed separately or in the shape of mixed fabrics,provided that the animal fiber is dyed Prussian blue (Williamsons blue)either before or af ter the oxidation.

The best way for producing Prussian blue on animal fibers is to apply abath of potassi um ferricyanid and sulfuric acid. The production of avery dark blue is not necessary. N or will this treatment weaken thevegetable fibers contained in mixtures with animal fibers, provided thatno greater quantity of sulfuric acid is used than that necessary for thedecomposition of the potassium ferricyanid. Tin salt may be added, butdoes not offer any advantage. Potassium ferrocyanid may also be used,but the color obtained with it is not so pretty as that obtained withferricyanid. Instead of potassium salts of hydro-ferricyanic acid or ofhydro-ferrocyanic acid other salts of these acids, or the cyanids orcyanurets of manganese and potassium, or of manganese and sodium, or ofchromium and potassium, or of chromium and sodium, or of cobalt ornickel, or copper or uranium with potassium or sodium, or sodiumnitroprussid or other nitro-prussids may be employed. The action of thePrussian blue has not yet been elucidated, as it seems it does notonlyact physically to intensify and shade the black color, but itappears to have also chemically a very importan t action in thepro cessof dyeing by means of oxidiation-black. The greening (aging) processtakes place in the usual manner, care being taken that the fibers willnot become dry, but remain moist. The chroming takes place subsequentlyin the usual manner. On pure animal fiber the black color may bedeveloped also by steaming. Finally the material is washed and soaped.The treatment of the animal fiber with potassium-ferrocyanid and acidmay be performed after (instead of before) the greening (oxidation)process. I11 either case a fast oxidationblack may be produced.

The anilin salt or anilin-oil may be replaced by equivalent quantitiesof diphenylamin salt and base or by other organic amins and their salts.These substitutions, how ever, cause a variation in the shade of blackproduced by the process.

Having now described my invention, What I desire to secure by a patentof the United States is 1. The method of producing oxidationblack uponanimal fibers, characterized by dyeing the animal fibers blue by meansof cyanids and acids before the oxidation-black process, substantiallyand for the purpose as described.

2. The method of producing oxidationblaok upon animal fibers,characterized by dyeing the animal fibers blue by means of cyanids andsulfuric acid before the oxidation-black process, substantially and forthe purpose as described. i

In witness whereof I have hereunto set my hand in presence of twowitnesses.

FRANZ KONITZER. i/Vitnesses:

GUSTAV TROMMER, HERBERT SMITH.

